Switch to pygfx?

[schlegelp]

pygfx is starting to stabilize (binaries, documentation, features, etc.). I ran some tests and it's impressively fast:

• large FlyWire neuron with 6.9M faces at 30fps (with vispy I get around 3fps)
• 844 FlyWire Kenyon cells with a total of 51.4M faces at ~8fps - slow but still useable

Should at some point look into whether we can replace vispy.

[schlegelp]

Ran some more tests and I'm really happy with performance.

WIP in this branch: https://github.com/navis-org/navis/tree/pygfx

TODOs:

• implement conversion of navis into pygfx objects (aiming for ~ feature parity)
• figure out how to make the viewer non-blocking from ipython REPL (check how fastplotlib does it)
• test in Jupyter environments (via jupyter_rfb)
• expose pygfx backend through plot3d()

Extension aims:

• refactor plotting backends to reduce redundancy (I'm thinking a Plotter abstract base class and subclasses of PlotterPlotly, PlotterMatplotlib, etc)
• consider replacing matplotlib with pygfx for 2d plots (see this example for SVG exports)

Update [08/04/2024]:

I offloaded the new Viewer into a separate, general purpose library called Octarine.